Various automated systems for forming and cutting surgical suture tips exist or are known in the art. In one such machine, means for simultaneously advancing in parallel at least six separate strands of suture material, and six independent tensioners for maintaining respective parallel portions of each of the six strands at a preset tension are provided. Once a predetermined length of suture material had been advanced by the advancing means, a horizontal heater bar (positioned perpendicular to the six suture strands) is actuated by an electronically controlled solenoid which moves a planar heater bar into contact with one side of the suture strands for a predetermined dwell time. Once the predetermined dwell time has elapsed, the solenoid retracts the heater bar to its original position, and the heat exposed (or heat-stiffened) section of suture material is advanced to a cutting station. At the cutting station, the heat-stiffened section of suture material is cut at its midpoint, thereby producing a suture with two stiffened ends. Other mechanisms for forming and cutting surgical suture tips are shown in U.S. Pat. Nos. 4,832,025, 4,806,737 and 5,226,336 to Coates. The system described in the Coates patents uses convective or non-contact heating to form suture tips.
Known systems for forming and cutting surgical suture tips suffer from two primary drawbacks. First, such systems typically produce a suture tip which lacks a substantially uniform cross-section. Second, such systems typically cut the suture tip in an imprecise manner, thereby leaving a cut end which may be irregular or distorted in shape. From a manufacturing standpoint, suture tips having non-uniform cross-sections and/or irregular or distorted cut ends are undesirable because, among other things, such sutures are difficult to insert into needles.
It is therefore an object of the present invention to provide a surgical suture having a tip with a substantially uniform cross-section and a precisely cut end which may be easily inserted into a needle.
It is a further object of the present invention to an automated system and method for manufacturing surgical sutures having tips with substantially uniform cross-sections.
It is a still further object of the present invention to provide an automated system and method for making surgical sutures with tips having precisely cut ends.
These and other objects and advantages of the invention will become more fully apparent from the description and claims which follow or may be learned by the practice of the invention.